1998 CEMC Gauss (Grade 7) Problems/Problem 6

Problem

In the multiplication question, the sum of the digits in the four boxes is:

[Multiply using long multiplication. Find the sum of the four numbers in the thousands place column.]

Solution

Multiplying, we find that the numbers in the thousands place column are 1, 9, 1, and 2 respectively. Adding yields a sum of 12, so the answer is

-edited by coolmath34

If anyone knows the LaTeX to show long multiplication, any help would be appreciated.

-edited by De-math-wiz

Solution

While doing the long multiplication the numbers in the thousand place are 1, 9, and 2 respectively. When added the sum is 13, so the answer is (A) 13

879 x 492 = 432,468

      879
  x   492
    1,758
   79,110
+ 351,600
= 432,468 

Therefore when 1, 9, 1, 2 are added together the total is 13, so (A) 13 is correct answer.